Southeast Queensland’s gated dams not be drained before an official La Niña event is declared

Gated dams will not be “proactively” drained before a La Niña event is officially declared, despite calls from Brisbane’s Lord Mayor.

Southeast Queensland’s gated dams will not be “proactively” drained before a La Niña event is officially declared, the state government has confirmed - rejecting calls from Brisbane’s Lord Mayor.

Water Minister Glenn Butcher said flood “mitigation efforts” could be taken a few months from now if the experts call for it.

Australia’s east coast has been told to brace for a potential third soggy summer in a row, with the Bureau of Meteorology recently shifting from “alert” to “watch” as it warns of a 70 per cent chance of a La Nina event.

Queensland Water Minister Glenn Butcher. Picture: NCA NewsWire / Dan Peled

Brisbane Lord Mayor Adrian Schrinner, on social media, queried if it was time for the state’s dam operators to “proactively lower dam water levels before another potential season of severe La Nina conditions”.

“During the February flood, Wivenhoe Dam levels went from 58.7 per cent to 183.9 per cent (including flood compartment) in just a few days,” Cr Schrinner said.

“A lack of Government focus on new water sources to match rapid population growth means that dam operators face the difficult balance between preparing for droughts and preparing for floods.”

As of Tuesday afternoon, Wivenhoe Dam was at 90.9 per cent supply capacity, Somerset Dam at 82.5 per cent and North Pine was at 68.2 per cent supply capacity.

Floods

Wivenhoe dam is on the Brisbane River, in the Somerset Regional Council area, about 80km from the city and is South East Queensland’s largest water storage dam.

It is the main supply of water for Brisbane and the greater Ipswich area, according to SEQ Water.

Somerset Dam is in the Somerset region with its main purpose being the supply of potable water for the Brisbane, Gold Coast and Logan City regions.
The North Pine Dam is built over the North Pine River about 5km from Petrie, north of Brisbane.

It stores drinking water for the people of north Brisbane and Moreton Bay.

Seqwater has opened the sluice gates at Somerset Dam following recent heavy rain in the catchment. The water will top up Wivenhoe Dam. Picture: Cassandra Cooney

Mr Butcher said the flood compartments of Wivenhoe and Somerset dams, collectively able to store 2.78 million mega litres of water – almost double the supply capacity – were empty and ready.

“We’re confident at the moment that we’ve got things in place ready to go, with that flood mitigation ready and waiting,” he said.

“But we may have to take some other strategies as the season unfolds.”

He noted this could include releases from Wivenhoe or Somerset should early rain indicate falls would be within the catchment areas.

Brisbane Lord Mayor Adrian Schrinner. Picture: Matthew Poon

Mr Butcher said the upcoming wet season, according to the government’s experts, would be similar to the drenching experienced in February this year.

But the La Nina has not been officially declared and he said the experts weren’t yet advising the dams be drained.

“Releasing water at an early stage now and the rain doesn’t turn up, then it’d be a different story… (we’d be) saying well why was the water released when it didn’t have to,” Mr Butcher said.